Identification Guide: Common Insects & Pests

Leafroller, oblique banded (Choristoneura rosaceana)

Leafrollers are caterpillars which feed protected by the rolled-up leaf of the host plant. This species will also chew holes in rosebuds, and feeds in fruits, vegetables, ornamental trees and shrubs. The pale green, black headed larvae may begin by mining leaves but will ultimately feed in rolled leaves or tie leaves together.

Leafroller, Fruittree (Archips spp.)

The 1/2 to 3/4 inch long caterpillars are green with shiny black heads. They roll or tie leaves up and feed inside the protected area. The eggs are laid in flat irregular masses on the stems. These masses can over winter but can be destroyed with dormant oil applications in the winter.

Leafroller, Omnivorous (Platynota spp)

This leafroller also feeds in flowers, vegetables, citrus, subtropical fruits, and various ornamentals. The larvae are yellowish or greenish brown with a stripe down the back.

Looper, Omnivorous (Sabulodes spp)

In addition to roses this insect feeds in avocado, citrus, fruit trees and dozens of ornamental plants. The larvae can vary in color from pale yellow, to pink or pale green with black, brown, or green stripes. The 1 to 2 inch long mature larvae has three pairs of legs behind its gold colored head and two additional pairs of legs near the rear.

The young larvae may feed on the leaf surface while the mature larvae will consume the entire leaf of leave only the midrib or large veins.

Tent Caterpillars (Malacosoma spp.)

The 1 to 2 inch mature larvae coloring varies by species but most are covered with tufts of hair. Some like the Western species spin large web under which they feed.

Orange Tortrix (Argyrotaenia spp.)

Is an important pest in citrus, avocado, raspberries and many ornamentals. The larvae is dirty-white in color with a dark brown head. It lays cream colored, sculptured disks in overlapping masses on both leaf surfaces.

Io Moth (Automeris io)

This large caterpillar is found in the eastern U.S. and west to New Mexico but is a problem on roses in Florida. It is pale green with a broad brown or reddish stripe, underscored with white along each side of the body. It has six defensive rows of branching green spines tipped with black. These spines can be poisonous to some people.

Aphids

There are many different species of aphids that feed on Roses. They vary from green, yellow, white, brown, purple, red, or black. They are typically small (1/8 inch) soft bodied, and pear shaped. They have a pair of cornicles (exhaust pipes) that project from the rear end of their abdomen. This feature distinguishes them from other insects. Their mouths are hollow tube like structures that pierce the plant so that sap can be sucked out. Aphids secrete honeydew which is rich in sugar and is an attractive food source for ants. It is also the medium for the growth of the black mold "sooty mold" to grow. Sooty mold doesn't damage the plant directly but when dense enough will inhibit the plants photosynthetic capacity. Aphids typically cause leaf curl, stem and flower distortion, yellowing, and leaf drop.

Japanese Beetles

Japanese Beetles are oval shaped and just under 1/2 inch long. They are shiny, metallic green with coppery brown wing covers and tufts of short, whitish hairs along the side. The larvae feed on the roots of grasses and herbaceous plants. The adults will congregate on flowers and individual plants devouring the flowers and foliage.

Rose Budworm (Pyrrhia spp.)

Budworms are small caterpillars that feed in or on opening flower buds. There are two types of Rose Budworms one is green with black spots and dark longitudinal stripes. The other has whitish orange markings on the back.

European Earwigs (Forficula auricularia)

European Earwigs (Forficula auricularia) These night-feeding insects are dark brown, 5/8 inch long with a pair of sharp pinchers at the tip of the abdomen. Earwigs feed on young tips, leaves, and flowers chewing holes through them. The older earwigs work on the blossoms, eating stamens and bases of the petals. They hide during the day under wood piles, along fences, and foundations.

Sawflies

Sawflies are insects related to bees and wasps. Almost all sawflies feed on plants in the larval stage. The larval are easily mistaken for caterpillars. There are several sawfly larvae that attack roses.

Bristly Rose Slug (Endelomyia spp., Cladius spp.)

Bristly Rose Slug (Endelomyia spp., Cladius spp.) The 5/8 inch long slug like larvae can be yellow green to pale green. When mature they have bristle like hairs on their bodies. Young larvae skeletonize the lower leaf surface, later they eat holes clear through.

Curled Rose Sawfly (Allantus spp.)

Curled Rose Sawfly (Allantus spp.) curls like cutworms. Like Bristly Rose Slug it begins as a leaf skeletonizer but eventually consumes entire leaves. The 3/4 inch long larvae has a yellow brown head, is metallic green with white dots, and grayish white underneath. The larvae pupates in the pruned ends of the rose canes.

Scale insects

Pictured: Soft Brown Scale, San Jose Scale, Cottony Cushion Scale, Black Scale

Scale insects are a very large group of plant feeders, many species feed on roses. They are related to aphids, and mealybugs and like those insects the soft scale species secrete copious amounts of honeydew (a sugary substance which black sooty mold grows on). Scale are easily overlooked because they are small, (1/8 to 1/4 inch) shell covered, immobile, and do not resemble other insects. Scale have sucking mouthparts and can cause your plants to appear water stressed, or yellowing foliage. Heavy infestations can kill entire branches. Scale insects can be divided into two groups armored or soft. Armored scales that attack roses are: Red Scale, Greedy Scale, San Jose Scale and Lantania Scale. Soft scales that feed on roses are: Black Scale, Soft Brown Scale, Oleander Scale, Olive Scale, and Rose Scale. Most scales can be controlled with winter dormant sprays, but they are also vulnerable at the crawler stage when the young are mobile an move in mass to establish new feeding sites. This generally occurs in the spring.

Spittlebugs or Froghoppers (Philaenus spp.)

Spittlebugs aka Froghoppers (Philaenus spp.) is a 1/4 inch long sucking insect that resembles a robust leafhopper. Pale straw, to brown colored they are most easily identified by the frothy spittle that covers them. They generally do not seriously damage the plants and can be washed off with a strong stream of water.

Rose Leafhopper (Edwardsiana spp.)

Rose Leafhopper (Edwardsiana spp.) is a creamy white to light yellow colored sucking insect. Feeding damage is characterized by stippling, yellowing, and sometimes slight curling of the foliage. The 1/8 inch long adults lay eggs on the rose canes that can overwinter there.

Bluegreen Leafhopper

Flower Thrips (Frankliniella spp.)

Flower Thrips (Frankliniella spp.) Have rasping sucking mouthparts and feed protected inside the rosebuds. The buds often turn brown on the petal edges, often petals staying stuck together. If they open it is often partially with distorted blooms. The thrips are alligator shaped and very small (1/20 inch) but are easily detected by opening a flower and shaking it vigorously over a white sheet of paper.

Grasshoppers

Short horned grasshoppers are moderately long insects that are called short-horned because their antennae are much shorter than their body as opposed to Katydids which have long antennae. Grasshoppers are day feeders that are difficult to control because they are quite mobile and will move when disturbed.

Greenhouse Whitefly (Trialeurodes vaporariorum)

The adults are 1/16 inch long and powdery white. Their colonies of 30 to 40 are found on the undersides of the foliage. The immature are immobile sucking insects that secrete honeydew and blacken the foliage with sooty mold. Feeding damage can also prematurely yellow the foliage. Several insecticide applications on 4 to 6 day intervals are generally needed to control this pest.

Giant Whitefly (Trialeurodes vaporariorum)

Raspberry Horntail (Hartigia cressoni)

Raspberry Horntail (Hartigia cressoni) western species

Rose Stem Sawfly (Hartigia trimaculata)

Rose Stem Sawfly (Hartigia trimaculata) eastern species Segmented white colored larvae about 1 inch long when mature. During the spring the adult females insert eggs under the tender bark on the new growing tips. The larvae can be found spirally girdling the tips of the canes, or in the pith of the cane causing wilting and die-back. These canes should be removed and destroyed.

Rose Midge (Dasineura rhodophaga)

Rose Midge (Dasineura rhodophaga) is a tiny fly only 1/20 inch long. These adults lay their eggs under the sepals of the flower buds and on the young tender growth. The white maggots hatch in 2 to 3 days and grow to 1/12 inch long. They feed at the base of the flowers, in buds or on the upper side of leaves and leaf petioles.

Rose Chafer (Dasineura rhodophaga)

The slender, tan colored adult beetles are 1/3 to 1/2 inch long with prominent long spiny legs. The adults swarm in the late spring early summer and favor feeding on the flowers.

Fuller Rose Beetle (Pantomorus cervinus)

Adults are night feeding pale brown weevils, about 1/3 inch long with a broad snout. The damage is ragged notches from the margins of the foliage or feeding in the blossoms.

Rose Leaf Beetle (Nodonota puncticollis)

Pacific and Appletree flatheaded borers are generally attracted to diseased, stressed or injured plants. The 1/2 inch female beetles lay their eggs in bark wounds caused by disease or injury. The grubs are 1 1/4 inches long, yellowish white, rather slender, broad and flat in front and narrow and tapered toward the rear. The grub burrows under the bark until full-sized, then bore deeper into the wood. Overlying bark is discolored, often slightly sunken. Damage can kill canes. Prevent infestation by maintaining good cultural practices. Remove and dispose of infected canes. Insecticides are not recommended because they work on the insect only at entrance or emergence and are not effective against the larvae underneath the bark.

Leafcutting bees (Megachile spp.)

The very precise circular or semicircular holes cut from the margins of the foliage are cut by the 1/2 inch robust Leafcutting bee. The ovals line the bottom and sides of their nests which are often built in wood, hollow stems of woody plants, cavities of dead twigs, or in the pithy stems of plants like dahlias. The circles are used to cap each cell after a egg has been laid inside. Bees are important pollinators and should not be killed. Their damage is superficial, we recommend you admire the precision of their pruning work.

Small Carpenter Bees (Ceratina spp.)

This 1/3 inch long bee is a pith borer. They prefer nesting in tunnels in the pith of roses. Look for them during the season when the cane shows wilting or sawdust protruding from the stems. Remove the stem and reveal the yellowish curved maggots by cutting the stem length wise. Some try to discourage re infestation by covering the stem cut by inserting a thumbtack. Another method is to seal the cut with Rose Stick Cane Sealer.

Rose Stem Girdler (Agrilus spp.)

This 1/3 inch long greenish colored beetle lays its eggs under the bark where the flathead borer make 1 or 2 spiraling mines around the cane. These mines sometimes swell and split. The control measure is to prune out the swollen stems in the spring.

Nematodes: Root Lesion Nematode, Dagger Nematode, Root Knot Nematode

Pictured: Root Knot Nematode

Nematodes are microscopic roundworms usually less than 1/20 of an inch in length. Most species feed in or on the root systems of plants. Heavy populations can cause stress, general decline, stunting, yellowing, premature defoliation, and even dieback. Nematodes are very difficult to identify because of their size, and feeding site location. Of the three most common species that attack roses, Root Lesion Nematode, Dagger Nematode, and Root Knot Nematode only Root Knot Nematode has easily visible symptoms. These are the numerous galls or nodules that form along the roots. Similar decline symptoms may be caused root or vascular diseases, insect borers or root feeders, or poor cultural practices. If none of the above mentioned reasons for unhealthy plants are obvious you may try sampling for nematodes.

Rose Curculio (Rhynchites bicolor)

The adults are 1/4 inch red to black weevils with prominent long stouts. The flower buds have holes punched in them. The open flowers can be riddled with holes and ragged in appearance. Holes can also be gouged in green canes.

Spider Mites (Tetranychus spp.)

Pictured:spider mite damage and webbing two-spotted spidermite, spider mite webbing.

Spider mites (Tetranychus spp.) are chlorophyll sucking spiders, greenish to pink in color about the size of ground pepper. They prefer feeding on the underleaf, light populations cause a flecking of the foliage. Damaged foliage can become bleached, dried up, and ultimately drop. Spider mites require several applications on 7 to 10 day intervals taking care to get good underleaf coverage.

Spotted Cucumber Beetle (Diabrotica spp.)

Spotted Cucumber Beetle & Western Spotted Cucumber Beetle (Diabrotica spp.) The adults are greenish yellow, with 12 black spots, a black head about 1/4 inch long. The adults will eat foliage but prefer to feed in the flowers.

Ladybird Beetle (Ladybug)

Katydid
(Pictured on yellow rose flower)

Katydids are sometimes referred to as long-horned grasshoppers. They are in the same family and are plant feeders but are not classified as serious garden pests. Control measures are not usually necessary for this insect. Sometimes egg clusters can be found layed on plant stems. The eggs resemble scale insects but are not randomly placed but are organized in a neat linear pattern.